Dow - my name is Dowson - derivative?

Hello! My maiden name is Dowson and I was always told that it meant son of Dow and that we belong to the Davidson clan. I replied to Edith Tippett's message re the Origins of Dow, 21 June I think it was, yesterday.I am just beginning to search my fathers' family tree on the Dowson side and any help would be greatly appreciated! My great grandfather's name was Parkin Dowson and he was born in Durham England in about 1875. He married a Caroline Kelson in 1897. She was born in Victoria Australia. They had 11 children between 1898 and 1923.